a. Field of the Invention
The present invention relates generally to window covering systems and, in particular, to traverse track mounting sytems suitable for use in window covering systems and to window covering systems using the carriers.
b. Definitions and Applicability
Typically, as used in the industry, "blinds" specifically refers to slat structures such as so-called venetian (horizontal slat) blinds, or vertical slat blinds, or so-called mini-blinds, or to flat, sheet structures such as the coverings used in roller blinds. "Covers" typically refers to pleated folding structures such as single pleat structures and box, hollow and cellular pleat structures. In this document, "cover" and "blind" are frequently used generically, in that "cover" includes "blind" and vice versa. It is believed the meaning which is intended--the generic or the specific--will be apparent from the context. Also, if and where used here, the terms "box" pleat blind, "hollow" pleat blind and "cellular" pleat blind are used interchangeably. Also, the words "carrier," "trolley" and "roller" are used interchangeably.
The present invention is applicable generally to vertically oriented window covering systems, including slat, folded pleat and cellular pleat covers. It is understood that "window," as used for example in "window covers," includes windows, doorways, openings in general and even non-opening regions to which "window coverings" are applied for decoration, display, etc.
The pleated blinds described here may be formed from lightweight fabric, which is effective in limiting total weight of the blind system. A series of pleats is formed in the fabric cover, for example, for providing a pleasing form to the cover, and for enabling the cover to be easily folded to facilitate opening and closing the blind. The lightweight fabric has a high degree of light transmission, for maximizing light transmission through the blind system when slats are in an open position. The fabric cover, however, has a high degree of diffusion for light transmitted therethrough. This combination of high transmission and high degree of diffusion is effective in providing privacy when the blind is open, while still providing adequate transmission of light through the cover and, thus, adequate daylight illumination. The fabric blind preferably is of pleated fabric such as the RIDEAU.TM. pleated cover.
c. Current State of the Relevant Field
Traverse tracks for vertical blinds include carriers or trolleys having wheels which are captured by the track, so that the carriers traverse along the track. Typically, the wheels are small, smaller than the longitudinal length of the carriers, to minimize interference between the wheels of adjacent carriers and thus permit the carriers to be closely packed when the associated blind is open (with the carriers bunched together). However, the use of small wheels increases rolling friction between the wheels and the track, and thus increases the force required to open and close the blind. In addition, the carrier mounting may be somewhat unstable and subject to pivoting and tilting.